This invention is directed to a vortex inhibiting spherical tank outlet structure wherein the closed tank outlet is positioned away from the local gravity vector in the tank.
When the tank is used to supply liquid, the ingestion of vapor from over the liquid into the liquid outlet line may cause serious problems. In one case, where the tank is pressurized with an inert gas and liquid fuel is supplied from the tank outlet, the ingestion of pressurizing gas into the outlet line is serious and may cause flame-out where the fuel is burned, leading to overheating, chugging and possibly explosion.
Prior efforts led to the conclusion that antivortexing baffles were the best solution to the problem, and these were universally adopted. However, different problems occur in zero and low gravity force operations.
In spinning spacecraft, it can be argued that a coriolis type moment is produced by an interaction of fluid motion moving radially inward towards the drain, combined with the angular-spin rate. This moment could be the driver in the vortexing, but this is difficult to qualify. Other possibilities of swirl initiation are angular rates left over from satellite orientation and random inputs caused by orientation correction pulses. These possibilities become particularly apparent in spacecraft structures where the local gravity force is either zero or much smaller than earth gravity, but the same concepts apply to earth-bound tanks. Such earth-bound tanks is a 1 G environment can also benefit from the invention defined herein. Accordingly, there is a need for a means for inhibiting vortexing at the outlet of a tank structure.